1. Technical Field
The present invention relates to handsfree systems and incoming call answering methods in the handsfree systems, and more particularly, a handsfree system to answer an incoming call handsfree and an incoming call answering method in the handsfree system.
2. Description of the Related Art
Automobile telephones are used handsfree by installing an in-vehicle apparatus in a vehicle and by connecting a cellular telephone to the in-vehicle apparatus. The in-vehicle apparatus has intelligent functions, such as a handsfree function (automobile telephone function), an in-vehicle navigation function, and an audio function.
According to the in-vehicle apparatus, when a user originates a call in the vehicle, the in-vehicle apparatus is connected to a recipient's telephone via the cellular telephone, a wireless base station, and a public telephone network, so that the user can talk with the recipient. Also, the user can talk with a caller by answering an incoming call from a telephone of the caller.
In a first incoming call answering method in the in-vehicle apparatus having the handsfree function, when an incoming call arrives, a ringing tone is generated or a message indicating the arrival of the incoming call is displayed on a display unit. Then, when a user performs a predetermined operation, incoming call answering processing starts, and connection with a caller's telephone is established.
In a second incoming call answering method, after an incoming call arrives, incoming call answering processing automatically starts in accordance with a timer or the number of ringing tones (the number of ringing times) functioning as a trigger, and connection with a caller's telephone is established.
In a third incoming call answering method, a user pressing any hard key is regarded as operating a conversation start key (an any-key answer function), incoming call answering processing starts, and connection with a caller's telephone is established.
As described above, the in-vehicle apparatus has the in-vehicle navigation function and the audio function as well as the handsfree telephone function. Also, operation members, such as keys, buttons, and a volume control, arranged on an operation panel and other operation members arranged around a display unit are categorized into individual operation members unique to corresponding functions and common operation members. For example, an up or down button used as a zoom-in or zoom-out button for maps for navigation also functions as a volume-up or volume-down button for handsfree operation. When an incoming call arrives in the in-vehicle apparatus, common operation members come to be used as operation members for handsfree operation.
As described above, if an incoming call arrives when a user of an in-vehicle apparatus operates a button, for example, to zoom in (or out) a map in a navigation mode, the button function is changed so as to be used as a volume control for a handsfree telephone. However, the user may continue the operation thinking of the button as a zoom-in or zoom-out button for navigation. Thus, the volume of the handsfree telephone turns up (or down). Then, if the user starts a conversation with a caller by operating a conversation start key in accordance with the first incoming call answering method or if the user automatically starts conversation with the caller after a predetermined period passes in accordance with the second incoming call answering method, a loud voice of the caller is suddenly output or a voice of the caller is too quiet to be heard.
Also, in accordance with the third incoming call answering method (the any-key answer function), if the user continues zooming in (or out) the map, in other words, the user continues pressing the up or down button after the incoming call arrives, the same state as when the user operates the conversation start key (conversation state) occurs even if the user does not intend to perform incoming call answering processing.
Also, in the third incoming call answering method (the any-key answer function), if the user originates a call without recognizing the incoming call after the incoming call arrives, the user unavoidably answers the incoming call in contrast to the user's intention of originating a call.
FIG. 12 illustrates a known sequence for an incoming call. Before an incoming call arrives, operation members are used for navigation. A user operation UOP1 using an operation member is entered to a navigation system 3 through a user interface 4, and the navigation system 3 performs processing corresponding to the user operation UOP1. In this state, when the incoming call arrives in a handsfree system 2 from a cellular telephone 1, the handsfree system 2 changes the user interface 4 so as to be used for handsfree operation. If a zoom-in or zoom-out button for maps is operated when the incoming call arrives and the any-key answer function is active, continuing to operate the zoom-in or zoom-out button (user operation UOP2) in order to change the size of a map after the arrival of the incoming call is regarded as answering the incoming call, and a loud voice or a quiet voice of a caller may be output against the user's intention.
A handsfree system for causing a user to easily recognize the arrival of an incoming call is suggested in Japanese Unexamined Patent Application Publication No. 11-298574. According to this handsfree system, when an incoming call arrives, an incoming call answering screen that is remarkably different from other screens is displayed on a display so as to cause the user to recognize the arrival of the incoming call. Accordingly, the user recognizes the arrival of the incoming call, and performs an operation suitable for a handsfree telephone.
However, in the known handsfree system, the problems caused by continuing to operate the same button after the arrival of an incoming call cannot be solved. In other words, problems, such as a loud voice suddenly output from a caller, starting a conversation with a caller without performing answering processing, and answering an incoming call in contrast to an intention of originating a call, cannot be solved.